to much or not enough?

[jubal early]

I have a 90 gal. community Malawi tank which I keep well stocked with both mbuna & Hapochromis,(mostly Peacocks), along with several different Victorian Haps, and a M&f Cyrtocara moorii. I also have a 75 gal. set up the same way. Both have been running for over a year with no MAJOR problems except thet I cant seem to get the NITRATE level down. It's as high as 160 most times. I know , over crowding & feeding. I keep them both crowded because it really cuts down an the aggression, and I feed them both small amounts twice a day.
Could the problem be my filtration? The 90 has a EHEIM rated for a 100gal. tank, plus a Magnum canister rated for a 125 gal. It's also got a large sponge filter (well hidden) run by a air pump. I use Chem-Pro ion exchange bags in the Eheim, and super-pro ceramic rings in the magnum instead of carbon. The 75 is set up the same way,with the edition of a bio-wheel. Is this filtration OK? I get a lot of coating on the glass,which comes off easy but keeps coming back. Should I increase the Lake salts & Malawi buffer? Most of the fish spawn on a regular basis.
Please help a newbe that wants to learn and help promote Cichlid conservation.
Bobby

[Ken Boorman]

Hi,
As far as removing nitrates from your tank is concerned, filtration really doesn't do much. The nitrates will still be in contact with the water flow in your filter materials and are only really removed when you do your frequent water changes. I would try doing maybe 10% water changes as often as you can - daily wouldn't hurt the fish at all, just to see if the tests improve.
I think you should test your water before adding it to the tanks as well. Depending on where you are, tapwater sometimes carries comparitively huge amounts of phosphates etc and will effect your water chemistry every time you do one of the water changes.
Good luck,
Ken

[Lisachromis]

I would also make sure that you clean your filters more often as well. Leaving the dirty filter material in there also will reflect in the high(er) concentrations of nitrate.

[jubal early]

Thanks,y'all have been a big help.

[Willy]

You know that nitrate can have many many reasons.
First important is your waterchange every week,up to 50%.
Then the feeding and overcrowding(take out some fish i would say for a start).
In your country you use a lot of technichal stuff,and that is not always perfect.
Try to make a biological filter.
We,in my club in Holland make everything by ourselfs,including the fishtanks in any size you want.
but we are well known for our technical systemes,filtering,light and so on.
Lets say you have a tank with a front size of 1.50m and something like 90 gallons,then we make an almost same aquarium(a little bit smaller)under the tank with several department(including CO2 if needed).
The water runs out of the main-tank into this filter with help of a radiatorpump(stong enough for this tank of course).
On the other side it will go up thrue a compartment with lavastone,and then back into the maintank.
In this filtertank with a lot of different filterstuff(you can hide your heater,thermometer and other things there to)will bacteria breed there and brake off the nitrates.
Of course this need some time to develop.
give a new tank chance to develop,first plants,after two weeks maybe some fish,but never to many,this is always bad.
Don't forget that even the biggest tank is nothing in compare with nature.
Esspecially the rock-tanks without plants can have nitrate problems.
Maybe you should first change water every 2 days,and then see what happens,but i am sure there is some other problem in your tank that makes the nitrate go up so much.
Find it,maybe wood that is rotting or something else,i cannot see that from here.
I can only recommend a biologig filtersystem,sure for Lake Tanganjika and Malawi.
Good luck! Willy Bijker,Holland

[MatsP]

Sorry to spark off an old thread, but I'd like to add my 2 cents to the commentary.

First off, most Nitrate comes from the food you put in the tank, via some different routes, either through the fish or by bactera that breaks down any food that is left over. To begin with, this will produce ammonia(NH3), which other bactera convert into nitrite (NO2) and further to nitrate (NO3) by another lot of bacteria.

The nitrate is better than the two former, as it's much less poisonous.

Once nitrate has formed, there is only plants that will use nitrate up, and it's highly likely that a high nitrate level will also give growths of various algae (brown or green). If you don't do anything, the nitrate level will rise in the tank, and there's really only one way to reduce the nitrate level. That is to replace the water in the tank.

There is a process whereby bacteria will convert nitrate (NO3) to nitrogen(N2) and oxygen(O2), but this process is what's called anaerob, which means that it only happens in low/non-oxygen environments, something we don't want inside the tank. So there's little hope that this will actually happen at any large scale in the tank.

The sump-filter that Willy explains is a good solution, and if designed correctly, it can be used to create an anaerob region in the sump.

But it's relatively simple to get rid of the nitrate by doing more frequent, and perhaps larger water changes. Higher frequency is better than bigger water changes, simply because it helps maintain a lower average nitrate level, and the change isn't so great.

On one of my tanks (which is about 90L, 25 us gal), I change 40-45% of the water two-three times a week. It's got a lot of little baby fish in it, and is on the border to be overstocked, so large and frequent water-changes is the only way to keep the fish healthy.

--
Mats

[Bambi]

When I moved to keeping Cichlids from years of 'general community fish tanks' I always thought the idea of a 50% water change sounded risky, especially every week. I was used to having a healthy tank on a monthly 25% water change, but I stuck to the LSF advise and have done weekly changes of water from 30-50% since I set up the tank. I just trickle fill the tank direct from the tap (after adding water treatment to the tank) and the fish seem to love it, even though the water entering the tank is ice cold, as it fills up the 30 gallons over several hours the tank hardly drops in temperature at all.
All of my fish also crowd under the water entering the tank, they seem to enjoy the cooler water.......
I have had cery few deaths in my tank in the last 4 years and the water quality is always spot on.

oh and as to nitrates from food, definatley, after all fish poo is just decomposing food and uneaten food just sinks and rots in the tank. Always better to under feed your fish than over feed them.

[malawitangaluvr]

Being a hobbyist in both the Marine and African cichlid world, water changes have the most prolific affects on Nitrate levels. This is extremely evident in the Marine environment when looking at the survival of invertebrates, where any slight changes can have drastic outcomes. With keeping this in mind, the Rift Lake tanks can benefit the same way (especially being somewhat brackish), and I have found this to be the greatest control, next to feeding and filtration maintenance. By volume, water changes have a steadier control over elevated levels of toxicity.

[Lisachromis]

I have to comment here on the state of "African" waters that are being discussed. They are not brackish. They do contain salts, but not sodium salts (NaCl) which is what's needed to be brackish. Salinity is expressed by the amount of salt found in 1,000 grams of water. Therefore, if we have 1 gram of salt in 1,000 grams of water, the salinity is 1 part per thousand, or 1 ppt. Anything less than 5 ppt salinity is considered fresh water. Anything over 32ppt is considered oceanic salinity. Brackish is considered to be anything between 5 and 17ppt. Since the lakes are dealing with calcium chloride and not sodium chloride, they can't be brackish. I just don't want anyone to become confused and assume that their 'African' cichlids are brackish water fish.

[malawitangaluvr]

Good Point, LISACHROMIS. I did not mean to confuse anyone in regards to salinity, (and want to make that point known to this forum..) but to only bring about the point of consistent water changes. In any event, thanks for the clarification.

[faulty]

i just returned from Zambia and i am currently testing some of the water from Kafue river, the water seems to have a naturally high ph and low salinity further tests will be conducted soon and results will be posted. Speices there documented include kafue breem and Redbrested Tilapia amoungst other non Cichlid species.

[Lisachromis]

Looking forward to the results....

[polleni]

The tests which you have to run on this water is pH (which you already have) GH and KH. The latter is particularly important because, in contrast to what is believed generally, you can have a high pH with a very low KH. This means that the buffering capacity of your water will be minimal and, as the fish produce more and more acidic metabolic biproducts, your pH will change rapidly. Another issue is nitrates and microbial count. You can get one of those single use (rather cheap) sticks from Merch Darmstadt (I think) which you can dip in the water and will tell you in 48 hours if the water is safe. Some microorganisms are bound to be found but an excess should alarm you. A very good friend of mine uses water from his own well and was happy for over 10 years when suddenly, following a large water change he lost half his livestock. Only days later he found out that a decaying rotent had polluted his water.. Of course, this can't happen in a river unless you collect water right over the dead body, but it shows that "nature's" water still needs to be checked.. If your water paremeters KH and GH are not ideal, you can still adjust them easily with a minimum cost by adding Calcium chloride (freely soluble, raises teh GH) and / or sodium bicarbonate (baking soda, soluble, raises the KH). After you get your results, please share them with this forum..

[Bas Pels]

The tests which you have to run on this water is pH (which you already have) GH and KH. The latter is particularly important because, in contrast to what is believed generally, you can have a high pH with a very low KH.

This is certainly the case. if one puts sodiumhydroxid into water, the pH will raise, but the KH not (not vcarbonate was added)

This means that the buffering capacity of your water will be minimal and, as the fish produce more and more acidic metabolic biproducts, your pH will change rapidly.

This, however, is not nessisarily the case. The most common buffer in aquarium circumstances may be carbonate, other buffers excist as well. One is phosphate, another could be calciumcarbonate, which does not dissolve, and thus does not influence the KH.

Still, a low KH will most often be a sign of little buffer capacity, and thus fast pH changes. However, is someone is having chemisty in school (or helping the kids with chemistry) this point might raise a lot of confusion.

Bas

[polleni]

The main buffer in water (freshwater) is (and should be) carbonates only. Phosphates, oxalates, citrates and many other buffers may exist but they will not be able to "hold" the pH of your tank should need arise. That apart, the metabolite which is always in the water is carbon dioxide released by the fish - which is also absorbed by the atmosphere, or even added on purpose (planted, Amazon type tanks). In all those cases, KH is the only buffer which will respond to the change and keep the pH steady. That apart, buffering your tank with phosphates will also result in an algae outbreak which will be very difficult to control - inless you keep your water nitrate free. I agree that you can buffer your water using other types of buffers but I would prefer to rely on KH (which is also easily measured). From a chemist's point of view however, you are right.